Wax-based or liquid-based therapeutic compositions applied externally to the skin may be used as a means for conditioning skin, softening skin and relieving joint pain, among other uses. In such a treatment, the wax-based or liquid-based therapeutic compositions are often heated to a melting state or to a certain temperature and the body portion targeted for treatment, such as hands or feet, are brought into contact with the therapeutic composition. Current methods of melting bulk quantities of wax-based or liquid-based therapeutic compositions for dipping of hands or feet takes time (typically two-three hours), which is inconvenient for a commercial entity providing such therapy services. Further, repeated heating-cooling cycles of bulk wax-based or liquid-based therapeutic compositions for skin therapy reduces the effectiveness of the composition over time, creates a risk of biological cross-contamination, and poses potential health risks for the subjects under the therapy. Therefore, a need exists for improved methods and apparatuses associated with this type of therapy which provides fast, contamination-free, portable, user-friendly means for application of various skin therapeutic compositions.